Abdominal aortic aneurysm is associated with subarachnoid hemorrhage.

BACKGROUND: Although intracranial aneurysms (IA) and abdominal aortic aneurysms (AAA) share similar risk factors, little is known about the relationship between them. Previous studies have shown an increased incidence of IA in patients with AAA, though the rate of subarachnoid hemorrhage (SAH) in patients with AAA has not been described. OBJECTIVE: To use claims data with longitudinal follow-up, to evaluate the incidence of aneurysmal SAH in patients diagnosed with AAA. METHODS: We examined longitudinally linked medical claims data from a large private insurer to determine rates of aneurysmal SAH (aSAH) and secured aSAH (saSAH) in 2004-2014 among patients with previously diagnosed AAA. RESULTS: We identified 62 910 patients diagnosed with AAA and compared them 5:1 with age- and sex-matched controls. Both populations were predominantly male (70.9%), with an average age of 70.8 years. Rates of hypertension (69.7% vs 50.6%) and smoking (12.8% vs 4.1%) were higher in the AAA group (p<0.0001) than in controls. Fifty admissions for aSAH were identified in patients with AAA (26/100 000 patient-years, 95% CI 19 to 44) and 115 admissions for aSAH in controls (7/100 000 years, 95% CI 6 to 9), giving an incidence rate ratio (IRR) of 3.6 (95% CI 2.6 to 5.0, p<0.0001) and a comorbidity-adjusted incidence rate ratio (IRR) of 2.8 (95% CI 1.9 to 3.9) for patients with AAA. The incidence of secured aneurysmal SAH was proportionally even higher in patients with AAA, 7 vs 2/100 000 years, IRR 4.5 (95% CI 3.2 to 6.3, p<0.0001). CONCLUSION: SAH rate was elevated in patients with AAA, even after adjustment for comorbidities. Among risk factors evaluated, AAA was the strongest predictor for SAH. The relative contributions of common genetic and environmental risk factors to both diseases should be investigated.

Drivers of variation in 90-day episode payments after mechanical thrombectomy for acute ischemic stroke.

BACKGROUND: Although mechanical thrombectomy for acute ischemic stroke from a large vessel occlusion is now the standard of care, little is known about cost variations in stroke patients following thrombectomy and factors that influence these variations. METHODS: We evaluated claims data for 2016 to 2018 for thrombectomy-performing hospitals within Michigan through a registry that includes detailed episode payment information for both Medicare and privately insured patients. We aimed to analyze price-standardized and risk-adjusted 90-day episode payments in patients who underwent thrombectomy. Hospitals were grouped into three payment terciles for comparison. Statistical analysis was carried out using unpaired t-test, Chi-square, and ANOVA tests. RESULTS: 1076 thrombectomy cases treated at 16 centers were analyzed. The average 90-day episode payment by hospital ranged from $53 046 to $81,767, with a mean of $65 357. A $20 467 difference (35.1%) existed between the high and low payment hospital terciles (P<0.0001), highlighting a significant payment variation across hospital terciles. The primary drivers of payment variation were related to post-discharge care which accounted for 38% of the payment variation (P=0.0058, inter-tercile range $11,977-$19,703) and readmissions accounting for 26% (P=0.016, inter-tercile range $3,315-$7,992). This was followed by professional payments representing 20% of the variation (P<0.0001, inter-tercile range $7525-$9,922), while index hospitalization payment was responsible for only 16% of the 90-day episode payment variation (P=0.10, inter-tercile range $35,432-$41,099). CONCLUSIONS: There is a wide variation in 90-day episode payments for patients undergoing mechanical thrombectomy across centers. The main drivers of payment variation are related to differences in post-discharge care and readmissions.

Aberrant AICA Injury During Translabyrinthine Approach.

OBJECTIVE: To define a complication of the translabyrinthine surgical approach to the posterior fossa related to a rare variant of the anterior inferior cerebellar artery (AICA) that penetrated into the petrous temporal bone. PATIENT: A healthy 59-year-old male with a unilateral sporadic vestibular schwannoma. INTERVENTION: The patient elected to undergo a translabyrinthine approach for resection of a vestibular schwannoma. An aberrant loop of AICA was encountered during the temporal bone dissection within the petrous portion of the temporal bone. OUTCOMES: The patient suffered a presumed ischemic insult resulting in a fluctuating ipsilateral facial paresis and atypical postoperative nystagmus. RESULTS: MRI demonstrated an ischemic lesion in the vascular distribution of the right anterior-inferior cerebellar artery, including the lateral portion of the right cerebellar hemisphere, middle cerebellar peduncle, and bordering the right cranial nerve VII nucleus. His functional recovery was excellent, essentially identical to the anticipated course in an otherwise uncomplicated surgery. CONCLUSIONS: This case highlights the irregular anatomy of the AICA as well as the importance of thorough neurological exams in the postsurgical lateral skull base patient.

Minimizing SARS-CoV-2 exposure when performing surgical interventions during the COVID-19 pandemic.

BACKGROUND: Infection from the SARS-CoV-2 virus has led to the COVID-19 pandemic. Given the large number of patients affected, healthcare personnel and facility resources are stretched to the limit; however, the need for urgent and emergent neurosurgical care continues. This article describes best practices when performing neurosurgical procedures on patients with COVID-19 based on multi-institutional experiences. METHODS: We assembled neurosurgical practitioners from 13 different health systems from across the USA, including those in hot spots, to describe their practices in managing neurosurgical emergencies within the COVID-19 environment. RESULTS: Patients presenting with neurosurgical emergencies should be considered as persons under investigation (PUI) and thus maximal personal protective equipment (PPE) should be donned during interaction and transfer. Intubations and extubations should be done with only anesthesia staff donning maximal PPE in a negative pressure environment. Operating room (OR) staff should enter the room once the air has been cleared of particulate matter. Certain OR suites should be designated as covid ORs, thus allowing for all neurosurgical cases on covid/PUI patients to be performed in these rooms, which will require a terminal clean post procedure. Each COVID OR suite should be attached to an anteroom which is a negative pressure room with a HEPA filter, thus allowing for donning and doffing of PPE without risking contamination of clean areas. CONCLUSION: Based on a multi-institutional collaborative effort, we describe best practices when providing neurosurgical treatment for patients with COVID-19 in order to optimize clinical care and minimize the exposure of patients and staff.

A 72-Year-Old Female With Bow Hunter Syndrome: A Rare Surgical Approach to C4-5 Vertebral Artery Decompression: 2-Dimensional Operative Video.

Bow hunter syndrome is defined as vertebrobasilar insufficiency due to mechanical occlusion of the vertebral artery during head and neck rotation. In many cases, this is due to osteophyte formation, disc herniation, cervical spondylosis, tendinous bands, or tumors. Symptomatic disease may vary from inducing transient vertigo to posterior circulation stroke. Although digital subtraction angiography is the gold standard in diagnosis, the underlying pathology in bow hunter syndrome may be detected with doppler ultrasound, computed tomography (CT) angiogram, magnetic resonance imaging and angiogram, and diagnostic angiography with dynamic testing. In this case, a 72-yr-old female with a recent right-sided cerebellar stroke underwent operative intervention to decompress the right vertebral artery at C4-C5 in order to relieve symptomatic bow hunter syndrome. Preoperative CT angiogram revealed bilateral significant stenosis of the vertebral arteries at the C4-C5 level with follow-up diagnostic angiogram revealing complete occlusion of the right vertebral artery with the head rotated right (compared to 80% occlusion observed when the patient's head was rotated left). Prior to the procedure, the patient experienced lightheadedness, diaphoresis, dizziness, and a sensation of facial flushing exacerbated by rotating her head to the right. To relieve her symptoms, operative intervention was undertaken. To access the lateral osteophytes originating from the uncovertebral joint, a C4-5 discectomy is utilized. The vertebral artery was decompressed, and a standard anterior cervical fusion was performed. Postoperatively, the patient was stable and was discharged 1 d after surgery. Postoperative imaging showed adequate decompression of the right vertebral artery at the level of C4-5. The authors confirm that they have obtained, prior to submission, a written release from the patient authorizing use of this surgical video to be submitted and published in the journal Operative Neurosurgery, as well as consent to perform the procedure.

Complications in Patients Undergoing Microsurgical Clipping of Intracranial Aneurysms with Pre-existing Ventriculoperitoneal Shunts Following a Cranial Procedure.

INTRODUCTION: Patients with ventriculoperitoneal/pleural (VP) shunts occasionally must undergo subsequent craniotomy, craniectomy, or cranioplasty. Due to changes in pressure dynamics following shunt placement, we hypothesized that such patients may have an increased risk of developing symptomatic collections of extra-axial blood, fluid, and/or air postoperatively, leading to longer stays and worse outcomes compared to those undergoing cranial operations without a VP shunt. METHODS: From a retrospective cohort of patients who underwent cranial operations for management of cerebral aneurysms in 2005-2014, we identified patients who previously had a VP shunt placed, determined the temporal relationship between shunt placement and cranial operation, and investigated outcomes in those with and without a shunt. RESULTS: Of 818 patients who underwent cranial operations, 28 (3.4%) had a VP shunt. Four of these 28 (14.3%, 95% confidence interval [CI] 4.0%-32.7%) developed postoperative complications, compared to 42 of 790 (5.3%, 95% CI 4.0%-7.1%) without a history of VP shunt (P = .07). In addition, patients with a shunt were more likely to have longer cranial procedures (P = .04), longer hospital stays (P = .05), and more computed tomography scans during their craniotomy-associated admission (P = .002). Multivariate analysis, though not significant, demonstrated that the presence of a shunt contributed to the development of complications (odds ratio [OR] 2.24, 95% CI .70-7.13, P = .17). Length of surgery (OR 1.17, 95% CI 1.04-1.31, P = .01) and length of stay (OR 1.04, 95% CI 1.01-1.07, P = .01) were significantly longer in those with a postoperative complication. CONCLUSION: We found a nonsignificant trend toward increased postoperative complications in patients with a VP shunt who underwent a subsequent cranial operation.

Radiation dose reduction during neurointerventional procedures by modification of default settings on biplane angiography equipment.

BACKGROUND: Neurointerventional procedures represent a significant source of ionizing radiation. We sought to assess the effect during neurointerventional procedures of varying default rates of radiation dose in fluoroscopy (F) and image acquisition (IA) modes, and frame rates during cine acquisition (CINE) on total X-ray dose, acquisition exposures, fluoroscopy time, and complications. METHODS: We retrospectively reviewed procedures performed with two radiation dose and CINE settings: a factory setting dose cohort (30 patients, F 45 nGy/pulse, IA 3.6 µGy/pulse, factory CINE frame rate) and a reduced dose cohort (30 patients, F 32 nGy/pulse, IA 1.2 µGy/pulse, with a decreased CINE frame rate). Total radiation dose, dose area product, number of acquisition exposures, fluoroscopy time, and complications were compared between the groups. Means comparisons (t tests) were employed to evaluate differences in the outcome variables between the two groups. p Value <0.05 was considered significant. RESULTS: The reduced dose cohort had a significant reduction in mean radiation dose (factory, 3650 mGy; reduced, 1650 mGy; p=0.005) and dose area product (factory, 34 700 µGy×m(2); reduced, 15 000 µGy×m(2); p=0.02). There were no significant differences between cohorts in acquisition exposure (p=0.73), fluoroscopy time (p=0.45), or complications. CONCLUSIONS: Significant reductions in radiation dose delivered by neurointerventional procedures can be achieved through simple modifications of default radiation dose in F and IA and frame rate during CINE without an increase in procedural complexity (fluoroscopy time) or rate of complications.

Prasugrel is effective and safe for neurointerventional procedures.

BACKGROUND: Clopidogrel bisulfate and aspirin are routinely administered as dual antiplatelet agents for many neurointerventional procedures, especially for intravascular stent placement. Many patients are non-responsive to clopidogrel, either secondary to drug interactions or from variations of cytochrome P450 enzymes. Prasugrel (brand name Effient, Eli Lilly and Company, Indianapolis, IN, USA) is a new antiplatelet agent that has been utilized extensively in patients undergoing cardiovascular procedures but its safety and efficacy during neurointerventional procedures have not been evaluated. OBJECTIVE: To examine whether prasugrel is a safe and effective alternative to clopidogrel for neurointerventional procedures, especially in those patients who are either non-responders or allergic to clopidogrel. METHODS: The medical records of all patients undergoing neurointerventional procedures at our institution who received prasugrel between January 2009 and July 2011 were retrospectively reviewed. A systematic chart review was performed and the following data were recorded: demographics, aneurysm location, endovascular techniques, peri- and post-procedural complications, hemorrhagic complications, clinical outcome and angiographic outcome. RESULTS: 16 patients undergoing neurointerventional procedures received prasugrel over a 2 year interval. All patients who had follow-up studies of P2Y12 inhibition had immediate therapeutic response to prasugrel. There were no complications related to ischemic or intracranial hemorrhage. CONCLUSION: Prasugrel is a viable alternative to clopidogrel for patients undergoing neurointerventional procedures who are non-responders to clopidogrel. Further study is needed to evaluate the safety, efficacy and cost-effectiveness of prasugrel compared with clopidogrel for patients undergoing neurointerventional procedures.